Color/Spectral Stability of Mixed Halide Perovskite Light-Emitting Diodes

Abstract

Structuring metal halide perovskites with mixed halide anions is a promising strategy for attaining the desired bandgap and emission color for technological applications such as electroluminescent (EL) light-emitting diodes (LEDs) and ultrahigh-definition displays. However, these mixed halide perovskites suffer from severe EL spectral stability issues. During device operation, homogeneously mixed halide perovskite phases are prone to form halide-segregated domain phases with spatially inhomogeneous bandgap and emission color, which hinders practical use of perovskite LEDs (PeLEDs). In this review, a comprehensive survey is performed about the underlying driving forces for phase segregation, and representative strategies are discussed for the development of color/spectral stable mixed halide PeLEDs. Finally, the future directions and prospects are outlined regarding further enhancement of the color/spectral stability of mixed halide PeLEDs.